184 Letters, Extracts, Notices, ^c. 



of these having the long tail-streamers. The Rev. II. A. 

 Macpherson informs me that about two dozen adults and 

 birds " in change " have been killed between Walney Island 

 and the Sol way Firth. Dr. E. A, S. Elliot writes to me 

 from Kingsbridge^ South Devon, that a dozen examples have 

 been obtained in that neighbourhood. Many of these Skuas 

 appear to have been quite exhausted, and their stomachs to 

 have been empty. Judging from the specimens I. have 

 seen, 1 am inclined to think that the late Mr. Gould was to 

 some extent right in his supposition (' B. of Gt. Britain/ v.) 

 regarding the autumn plumage of the adults. I believe that 

 birds which are so far adult as to have bred during the 

 previous season may assume a few new grey-tipped feathers 

 on the back at least during the autumn; in other words, 

 that they " go back " a little. They may even get barred 

 feathers on the flanks and under tail-coverts ; though I 

 doubt it, for the Mevagissey example, upon which Gould based 

 his belief of this, is before me, and is clearly an immature 

 bird, which would not have bred till the following season. 

 But I expect that these traces of reversion cease as soon 

 as the birds become really mature. 



As regards distinctions between immature examples of 

 the Long-tailed Skua and the Arctic or Richardson's Skua 

 [S. cr'epidatus) , I have tried in vain to find any quicker and 

 readier test than that afforded by the shafts of the primaries. 

 In the Long-tailed Skua the two outer ones are bright 

 ivory-white, the third is generally dusky, and the rest are 

 distinctly brownish all the way, unless rubbed ; whereas in 

 the Arctic Skua all the shafts are white for the greater part 

 of their length, and are only dusky near the tips. Now and 

 then comes " a teaser, ■'"' but not often ; there is an adult in 

 the British Museum, which I am somewhat inclined to con- 

 sider may be a hybrid. When the shaft-test is not a success, 

 then other evidence must be brought to bear, but it usually 

 suffices. In the 4th ed. of 'Yarrell,' iii. p. 678, I unfortu- 

 nately made the slip of inserting the distinction for the 

 Long-tailed under the Arctic Skua ; and although this was 

 speedily corrected in the errata, and also in a special para- 



